Abstract P3-12-11: Clinical outcome in patients with surgically resected brain metastases from breast cancer: prognostic considerations regarding molecular status and established prognostic classification systems.

Abstract

Abstract Introduction: Incidence of brain metastases (BM) from breast cancer (BC) is increasing, paralleling increasing life expectancy of patients. However, biology, prognostic evaluation and treatment strategy are still a matter of debate. We analysed here a series of patients with resected brain metastases from BC to assess the actual prognostic factors in this specific population and the relevancy of widely accepted BM prognostic classification systems. Methods: we reviewed retrospectively all patients (n = 49) referred to our institution between December 2001 and July 2011 with available tumor tissue from resected breast cancer brain metastases. All patients underwent initial breast tumor surgery and surgical resection of the BM. Patients, tumor and treatment characteristics were recorded. Prognostic value of ER, PR, HER2 status of BM, age, Karnofsky performance status, Mini Mental Score (MMS), clinical features, number and topography of BM, systemic disease characteristics (response, metastatic sites), delay between primary tumor and BM diagnoses and treatment after neurosurgery were analyzed using uni- and multi-variate analyses. Results: Median age was 54 years (28–75). Median KPS was 80 (50–90). MMS was abnormal for 7 pts (14.3%). At BM diagnosis, 12 pts (24.5%) did not present extracranial disease and 15 (20.6%) had only one systemic metastatic site. After surgery, 83.7% of pts benefited from whole-brain radiotherapy and 79.6% from systemic therapy. Median follow-up was 25.6 months. Median cerebral progression-free survival (C-PFS) was 11.3 months (IC95:6.0–16.6) and median overall survival (OS) was 19.4 months (IC95:16.1–22.7). By univariate analysis, neither hormonal or HER2 BM status impacted survival. Similarly, molecular subtyping by IHC approximation (“basal”, ER− and PR−/HER2−;”luminal A”, ER and/or PR+/HER2−; “luminal B”, ER and/or PR+/HER2+; “HER2”, ER and PR−/HER2+) was not significantly associated with survival(p = 0.946). Abnormal MMS and multiple systemic metastases were associated with poor C-PFS (p = 0.009 for both) and poor OS (p = 0.006 and p < 0.001 respectively). Use of anti-HER2 therapy in HER2 positive patients (p = 0.003) impacted positively OS. Use of postoperative chemotherapy trend to be significant for C-PFS (p = 0.088) and OS (p = 0.100). By multivariate analyses, MMS (p = 0.012 for C-PFS, p = 0.009 for OS) and multiple systemic metastases (p = 0.020 for C-PFS, p < 0.001 for OS) remained significant, while the use of post-operative chemotherapy appeared relevant (0.013 for C-PFS and p = 0.006 for OS. Prognostic scoring systems (RPA, Nieder's Sperduto's and Niwinska's scores) were not significantly correlated to survival. Conclusions: Surgery seems to be bean effective treatment in oligometastatic brain disease of breast cancer patients whatever the hormonal receptor, HER2 or molecular subtype status of BM. MMS, presence of systemic metastases and use of postoperative systemic treatment are associated with better OS in this population whereas conventional established scoring systems are not significantly correlated to outcome. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-12-11.